Events

  • 2018
  • Past events
  • Seminar: NanoBioMedicine: Current technology, challenges and future guidelines

    Speaker
    Sonia Trigueros (University of Oxford)

    Description

    Nanotechnology is a new and exciting field that has the potential to transform the way medical and health solutions are being developed. In the Department of Physics, my group investigates new techniques and materials at a nanometric scale. In the Department of Zoology, my group applies this knowledge directly to know the most relevant biology on a single molecule scale and then use science and technology to solve the most urgent medical problems of the 21st century. During the talk, I will focus on describing the field of nanotechnology, current applications and the potential of future applications. I will also explain the latest basic research projects and medical applications that we are developing.

  • 2017
  • Seminar: Co-existing mesoscale patterns in bipartite networks: modularity, nestedness, in-block nestedness

    Speaker
    Javier Borge-Holthofer

    Description

    The identification of mesoscale connectivity patterns in complex networks has been central to the development of the field. Besides an interest in the methodological challenges, these patterns matter to the community inasmuch they result from a complex structure-dynamics interactions. It is in this context –network architecture as emergent phenomena– that nestedness and modularity arise as prominent macrostructural signatures to study. Furthermore, their prevalence in many natural and socio-technical systems has spurred research on the (possible) co-existence of both features. Here we will focus on particular socio-technical settings in which modularity and nestedness are observed together, and discuss some possible explanations and methodological problems. Then, we will present a brand new formulation of the problem where nestedness and modularity can coexist in the form of nested blocks within the network. Finally, we will discuss possible directions from here.

  • Seminar: Neuronal population activity responsible for rhythmic movements: Lognormality, spiking regimes and connectivity

    Speaker
    Rune W. Berg (University of Copenhagen)

    Description

    Motor patterns such as chewing, breathing, walking and scratching are primarily produced by neuronal circuits within the brainstem or spinal cord. These activities are produced by concerted neuronal activity, but little is known about the degree of participation of the individual neurons. Here, we use multi-channel recording (256 channels) in motor regions of the spinal cord to investigate the distribution of spike rates across neurons during generation of rhythmic movement. We found that the shape of the distribution is skewed and can be described as “log-normal”-like, i.e. normally shaped on logarithmic frequency-axis. Such distributions have been observed in other parts of the nervous system and been suggested to implicate a fluctuation driven regime (Roxin et al J. Neurosci. 2011). This is due to an expansive nonlinearity of the neuronal input-output function when the membrane potential is lurking in sub-threshold region. We further test this hypothesis by quantifying the irregularity of spiking across time and across the population as well as via intra-cellular recordings. We find that the population moves between supra- and sub-threshold regimes, but the largest fraction of neurons spent most time in the sub-threshold, i.e. fluctuation driven regime.

  • Seminar: Tumor clearance problem in dynamical cancer models with immunotherapy and global stability analysis

    Speaker
    Konstantin Starkov

    Description

    In this work we consider the ultimate dynamics of the Kirschner-Panetta model which was created for studying the immune response to tumors under special types of immunotherapy. New ultimate upper bounds for compact invariant sets of this model are given, as well as su cient conditions for the existence of a positively invariant polytope. We establish three types of conditions for the nonexistence of compact invariant sets in the domain of the tumor-cell population. Our main results are two types of conditions for global tumor elimination depending on the ratio between the proliferation rate of the immune cells and their mortality rate. These conditions are described in terms of simple algebraic inequalities imposed on model parameters and treatment parameters. Our theoretical studies of ultimate dynamics are complemented by numerical simulation results.

     

  • Avalanches and Large Events

    Organizers
    UBICS